Many oil, gas, and petrochemical pipeline operations, including pigging, swabbing, changes of meter parts, pipeline inspection maintenance (PIM), and the like, produce emissions of volatile organic compounds in associated venting or flaring operations. Pipeline operations also generally cover considerable distances, making it difficult and expensive to deal with these types of emissions.
Over the past few years, there has been more and more regulation of emissions of contaminants into the air. The passage of the Clean Air Act Amendments of 1990, the Kyoto Accord, and other regulations have set the stage for the reduction of air emissions worldwide. Reduction of air emissions is a priority for both countries and companies.
Air emissions in the United States are regulated by the Environmental Protection Agency (EPA). The EPA is the agency directly responsible for regulating air emissions in many states; however, in certain states the responsibility for regulatory compliance has been delegated to state agencies, e.g., in California, Texas, Louisiana, and others. Each state that has the responsibility for regulatory compliance must submit a State Implementation Plan (SIP) to the EPA for approval. The goal of the SIP is to implement federal standards in a manner that reflects the priorities and conditions of air emissions within the state. The SIP can be more stringent than the federal standards but not less so.
The Clean Air Act Amendments of 1990, and earlier legislation, divide a state or region into “attainment” and “non-attainment” areas. The “attainment” areas are those geographic areas considered capable of meeting federal standards for air quality. The “non-attainment” areas are those geographic areas that cannot meet or attain air quality standards. Those that emit pollutants into the air in “non-attainment” areas have to implement more stringent performance standards to reduce emissions. These more stringent standards extend to businesses in certain “SIC” code categories and can even extend to the general public for automobiles to meet certain emissions standards.
“Non-attainment” areas generally have more stringent criteria for certain air emissions. These criteria can include reduced allowable emissions of the oxides of nitrogen (NOx) or reduced allowable emissions of smog precursors such as VHAP's or HRVOC's. A “VHAP” is an acronym/abbreviation for ‘Very Hazardous Air Pollutant’ and HRVOC is an acronym/abbreviation for ‘Highly Reactive Volatile Organic Compound’. Since VHAP's and HRVOC's are smog precursors, recent SIP proposals to the EPA have stated that smog, a criteria pollutant, may be limited by controlling the amount of VHAP's and HRVOC's that are emitted to the atmosphere. Indeed, many regulated areas are beginning to place emissions “caps” on identified atmospheric pollutants, a “cap” meaning that there is a certain amount that a business entity can emit without an economic penalty and when the “cap” is exceeded then economic penalties are incurred.
With the introduction of the allowable emission “cap”, long-standing practices in the production, manufacturing, refining, transportation, and distribution of chemical and refined products must be examined. Recent SIP documents have resulted in regulations for HRVOC materials that define, limit, and establish the basis for documenting HRVOC emissions. HRVOC emissions events can be categorized as any of the following activities: a) venting HRVOC material to the atmosphere; b) flaring HRVOC material to the atmosphere; and c) fugitive emissions from equipment.
Venting and flaring of hydrocarbons has been done since the earliest days of oil and gas production. Early oil production had excess natural gas co-produced with the oil. Since there was no market for this co-produced gas, the gas was vented or flared. Old stories abound that the sky was lighted so brightly at night by flared gas that one could read a newspaper virtually anywhere oil was being produced.
As refining and petrochemical industries began to process “deeper into the barrel”, flaring and venting continued to play a primary role in plant safety. Pressure relief, with the accompanying venting and flaring, was then and continues to be one of the primary methods of assuring safety in refining and petrochemical facilities. Venting and flaring have long been accepted and unquestioned practices in the refining and chemical industries.
Over the past several years there has been increased environmental awareness that has resulted in laws and regulations implementing those laws to promote “cleaner” air and reduced earth-warming gases. Man has finally achieved a level of activity in emissions to the atmosphere and energy consumption that the earth's atmosphere is being profoundly affected. Regulatory response has been ever more stringent regulation of emissions to the atmosphere of “criteria” pollutants, including oxides of nitrogen, oxides of sulfur, earth-warming gases, carbon dioxide, volatile organic compounds, volatile hazardous air pollutants, and highly reactive volatile organic compounds. It should be noted that regulations generally do not eliminate certain activities, but rather promote regulatory “complexities” in the form of more stringent specifications and reporting requirements that create incentives to “do things a different way”. This is the case with both flaring and venting operations in industrial applications.
Accordingly, there exists a need for a method for reducing emissions of volatile organic compounds in pipeline and other operations and that is the subject of the present invention.